An anaphrodisiac is something that quells or blunts the libido. It is the opposite of an aphrodisiac, something that enhances sexual appetite. The word anaphrodisiac comes from the Greek prefix αν-, denoting negation, and the Greek goddess of love, Aphrodite.

Herbal anaphrodisiacs have been employed by various religious sects and orders throughout history. Most commonly, Chaste Tree (Vitex agnus-castus) has been used to normalize hormones in both men and women. An over-active libido is very often treated herbally by addressing poor adrenal function.

Rumours that the British Army put the 19th century anticonvulsant and sedative potassium bromide in soldiers' tea during World War II to damp soldiers' lust appears to be an urban myth. Given the long half-life of the drug in the body, a mildly sedated army would be unlikely to be an effective fighting force. A similar belief appears to exist in the United States about saltpeter in army coffee or in Russia about potassium bromide in army food.